// ========================================================================
// Copyright (c) 2009-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
package org.eclipse.jetty.http.gzip;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.zip.DeflaterOutputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.util.ByteArrayOutputStream2;
/* ------------------------------------------------------------ */
/**
* Skeletal implementation of a CompressedStream. This class adds compression features to a ServletOutputStream and takes care of setting response headers, etc.
* Major work and configuration is done here. Subclasses using different kinds of compression only have to implement the abstract methods doCompress() and
* setContentEncoding() using the desired compression and setting the appropriate Content-Encoding header string.
*/
public abstract class AbstractCompressedStream extends ServletOutputStream
{
private final String _encoding;
protected HttpServletRequest _request;
protected HttpServletResponse _response;
protected OutputStream _out;
protected ByteArrayOutputStream2 _bOut;
protected DeflaterOutputStream _compressedOutputStream;
protected boolean _closed;
protected int _bufferSize;
protected int _minCompressSize;
protected long _contentLength;
protected boolean _doNotCompress;
/**
* Instantiates a new compressed stream.
*
* @param request
* the request
* @param response
* the response
* @param contentLength
* the content length
* @param bufferSize
* the buffer size
* @param minCompressSize
* the min compress size
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public AbstractCompressedStream(String encoding,HttpServletRequest request, HttpServletResponse response, long contentLength, int bufferSize, int minCompressSize)
throws IOException
{
_encoding=encoding;
_request = request;
_response = response;
_contentLength = contentLength;
_bufferSize = bufferSize;
_minCompressSize = minCompressSize;
if (minCompressSize == 0)
doCompress();
}
/**
* Reset buffer.
*/
public void resetBuffer()
{
if (_response.isCommitted())
throw new IllegalStateException("Committed");
_closed = false;
_out = null;
_bOut = null;
if (_compressedOutputStream != null)
_response.setHeader("Content-Encoding",null);
_compressedOutputStream = null;
_doNotCompress = false;
}
/**
* Sets the content length.
*
* @param length
* the new content length
*/
public void setContentLength(long length)
{
_contentLength = length;
if (_doNotCompress && length >= 0)
{
if (_contentLength < Integer.MAX_VALUE)
_response.setContentLength((int)_contentLength);
else
_response.setHeader("Content-Length",Long.toString(_contentLength));
}
}
/* ------------------------------------------------------------ */
/**
* @see java.io.OutputStream#flush()
*/
@Override
public void flush() throws IOException
{
if (_out == null || _bOut != null)
{
if (_contentLength > 0 && _contentLength < _minCompressSize)
doNotCompress();
else
doCompress();
}
_out.flush();
}
/* ------------------------------------------------------------ */
/**
* @see java.io.OutputStream#close()
*/
@Override
public void close() throws IOException
{
if (_closed)
return;
if (_request.getAttribute("javax.servlet.include.request_uri") != null)
flush();
else
{
if (_bOut != null)
{
if (_contentLength < 0)
_contentLength = _bOut.getCount();
if (_contentLength < _minCompressSize)
doNotCompress();
else
doCompress();
}
else if (_out == null)
{
doNotCompress();
}
if (_compressedOutputStream != null)
_compressedOutputStream.close();
else
_out.close();
_closed = true;
}
}
/**
* Finish.
*
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public void finish() throws IOException
{
if (!_closed)
{
if (_out == null || _bOut != null)
{
if (_contentLength > 0 && _contentLength < _minCompressSize)
doNotCompress();
else
doCompress();
}
if (_compressedOutputStream != null && !_closed)
{
_closed = true;
_compressedOutputStream.close();
}
}
}
/* ------------------------------------------------------------ */
/**
* @see java.io.OutputStream#write(int)
*/
@Override
public void write(int b) throws IOException
{
checkOut(1);
_out.write(b);
}
/* ------------------------------------------------------------ */
/**
* @see java.io.OutputStream#write(byte[])
*/
@Override
public void write(byte b[]) throws IOException
{
checkOut(b.length);
_out.write(b);
}
/* ------------------------------------------------------------ */
/**
* @see java.io.OutputStream#write(byte[], int, int)
*/
@Override
public void write(byte b[], int off, int len) throws IOException
{
checkOut(len);
_out.write(b,off,len);
}
/**
* Do compress.
*
* @throws IOException Signals that an I/O exception has occurred.
*/
public void doCompress() throws IOException
{
if (_compressedOutputStream==null)
{
if (_response.isCommitted())
throw new IllegalStateException();
setHeader("Content-Encoding", _encoding);
if (_response.containsHeader("Content-Encoding"))
{
_out=_compressedOutputStream=createStream();
if (_bOut!=null)
{
_out.write(_bOut.getBuf(),0,_bOut.getCount());
_bOut=null;
}
}
else
doNotCompress();
}
}
/**
* Do not compress.
*
* @throws IOException
* Signals that an I/O exception has occurred.
*/
public void doNotCompress() throws IOException
{
if (_compressedOutputStream != null)
throw new IllegalStateException();
if (_out == null || _bOut != null)
{
_doNotCompress = true;
_out = _response.getOutputStream();
setContentLength(_contentLength);
if (_bOut != null)
_out.write(_bOut.getBuf(),0,_bOut.getCount());
_bOut = null;
}
}
/**
* Check out.
*
* @param length
* the length
* @throws IOException
* Signals that an I/O exception has occurred.
*/
private void checkOut(int length) throws IOException
{
if (_closed)
throw new IOException("CLOSED");
if (_out == null)
{
if (_response.isCommitted() || (_contentLength >= 0 && _contentLength < _minCompressSize))
doNotCompress();
else if (length > _minCompressSize)
doCompress();
else
_out = _bOut = new ByteArrayOutputStream2(_bufferSize);
}
else if (_bOut != null)
{
if (_response.isCommitted() || (_contentLength >= 0 && _contentLength < _minCompressSize))
doNotCompress();
else if (length >= (_bOut.getBuf().length - _bOut.getCount()))
doCompress();
}
}
/**
* @see org.eclipse.jetty.http.gzip.CompressedStream#getOutputStream()
*/
public OutputStream getOutputStream()
{
return _out;
}
/**
* @see org.eclipse.jetty.http.gzip.CompressedStream#isClosed()
*/
public boolean isClosed()
{
return _closed;
}
/**
* Allows derived implementations to replace PrintWriter implementation.
*/
protected PrintWriter newWriter(OutputStream out, String encoding) throws UnsupportedEncodingException
{
return encoding == null?new PrintWriter(out):new PrintWriter(new OutputStreamWriter(out,encoding));
}
protected void setHeader(String name,String value)
{
_response.setHeader(name, value);
}
/**
* Create the stream fitting to the underlying compression type.
*
* @throws IOException
* Signals that an I/O exception has occurred.
*/
protected abstract DeflaterOutputStream createStream() throws IOException;
}